# Hardness Conversion Master vs Quench

The clearest difference is ads: Quench at none against Hardness Conversion Master's shown. Hardness Conversion Master's advantage is update cadence (every 3 days vs every 3 months). On price, in-app purchases, device support and iOS requirement there is nothing between them.

Both are free to download. Hardness Conversion Master sells 1 one-off in-app purchase and Quench sells 3 in-app purchases, starting at $1.99 per month. Whichever you choose, the download price is not the number that matters.

Hardness Conversion Master ships an update every 3 days, Quench every 3 months. The most recent releases landed on October 22, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Hardness Conversion Master | Quench |
| --- | --- | --- |
| Price | Free | Free |
| In-app purchases | Yes | Yes |
| Ads | Yes | **No** |
| Update frequency | **Every 3 days** | Every 3 months |
| Size | 259 MB | 4 MB |
| Requires iOS | 17.6 | **17.0** |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [POYU WANG](https://appshunter.io/developer/1883764660) | [慧慧 高](https://appshunter.io/developer/1887721875) |

## What reviewers say

### Hardness Conversion Master

[App page](https://appshunter.io/ios/app/hardness-conversion-master/id6760411989)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Pro | $1.99 | one-time |


### Quench

[App page](https://appshunter.io/ios/app/quench-knife-heat-treating/id6789909656)

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Monthly | $1.99 | per month |
| Yearly | $7.99 | per year |
| Lifetime | Free | one-time |


## Frequently asked questions

### Is Hardness Conversion Master free?

Hardness Conversion Master is free to download, with in-app purchases available.

### Is Quench free?

Quench is free to download, with in-app purchases available.

### Do Hardness Conversion Master or Quench have ads?

Hardness Conversion Master shows ads; Quench does not.

### Which is updated more often, Hardness Conversion Master or Quench?

Hardness Conversion Master ships an update every 3 days, and Quench every 3 months. Most recently, Hardness Conversion Master was updated on October 22, 2026 and Quench on October 25, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*